Author Correction: Impact of sacubitril/valsartan on implantable defibrillator eligibility in heart failure: a real-world experience.

Correction to: European Review for Medical and Pharmacological Sciences 2021; 25 (18): 5690-5700-DOI: 10.26355/eurrev_202109_26788-PMID: 34604961, published online on 30 September 2021. After publication, the authors applied to change the first two lines of Table II as the second column results were erroneously shifted in the first column. In this way, the results were quite difficult to understand. There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/26788.

Impact of sacubitril/valsartan on implantable defibrillator eligibility in heart failure: a real-world experience.

OBJECTIVE: Current guidelines recommend an implantable cardiac defibrillator (ICD) in patients with symptomatic heart failure and reduced ejection fraction (HFrEF; left ventricular ejection fraction [LVEF] ≤35%) despite ≥3 months of optimal medical therapy. Recent observations demonstrated that sacubitril/valsartan induces beneficial reverse cardiac remodeling in eligible HFrEF patients. Given the pivotal role of LVEF in the selection of ICD candidates, we sought to assess the impact of sacubitril/valsartan on ICD eligibility and its predictors in HFrEF patients. PATIENTS AND METHODS: We retrospectively evaluated 48 chronic HFrEF patients receiving sacubitril/valsartan and previously implanted with an ICD in primary prevention. We assumed that ICD was no longer necessary if LVEF improved >35% (or >30% if asymptomatics) at follow-up. RESULTS: Over a median follow-up of 11 months, sacubitril/valsartan induced a significant drop in LV end-systolic volume (-16.7 ml/m2, p=0.023) and diameter (-6.8 mm, p=0.022), resulting in a significant increase in LVEF (+3.9%, p<0.001). As a consequence, 40% of previously implanted patients resulted no more eligible for ICD at follow-up. NYHA class improved in 50% of the population. A dose-dependent effect was noted, with higher doses associated to more reverse remodeling. Among patients deemed no more eligible for ICD, lower NYHA class (odds ratio (OR) 3.73 [95% CI 1.05; 13.24], p=0.041), better LVEF (OR 1.23 [95% CI 1.01; 1.48], p=0.032) and the treatment with the intermediate or high dose of sacubitril/valsartan (OR 5.60 [1.15; 27.1], p=0.032) were the most important predictors of status change. CONCLUSIONS: In symptomatic HFrEF patients, sacubitril/valsartan induced beneficial cardiac reverse remodeling and improved NYHA class. These effects resulted in a significant reduction of patients deemed eligible for ICD in primary prevention.

Echocardiographic long-term follow-up of adult survivors of pediatric cancer treated with Dexrazoxane-Anthracyclines association.

AIMS: Cardiovascular disease is a well-recognized cause of increased late morbidity and mortality among survivors of childhood cancer treated with anthracyclines. Co-administration of Dexrazoxane has been shown to significantly reduce short-term and mid-term cardiotoxicity. Aim of this study was to assess cardiac function in long-term (>10 years) survivors of childhood tumors treated with dexrazoxane/anthracycline association. METHODS AND RESULTS: Twenty cancer survivors previously treated with co-administration of anthracyclines-dexrazoxane for childhood renal tumors or sarcoma and a control group of 20 healthy subjects were enrolled in the study. Echocardiographic measurements included 3D left ventricular (LV) ejection fraction (LVEF) and LV and right ventricular (RV) global longitudinal strain (GLS). Among cancer survivors group the median age at diagnosis was 5 years (1-17) and they were evaluated at median follow-up time of 21.5 years (10-26). No evidence of cardiac toxicity, as defined by current guidelines, was reported in all survivors. No significant differences in standard and deformation imaging parameters were observed between survivors and controls (3D LVEF 58 ±â€¯3% vs 60 ±â€¯5% p = NS; LV GLS -21 ±â€¯1% vs -21 ±â€¯2% p = NS; RV GLS -23 ±â€¯2% vs -23 ±â€¯5% p = NS). No second tumor was registered in dexrazoxane-treated survivors. CONCLUSIONS: Our findings may support the role of dexrazoxane as a useful strategy for cardio-protection in children undergoing anthracycline based treatment. However, large randomized trials are needed to confirm the cardio-protective role of dexrazoxane in pediatric setting at long-term follow-up.

Quantitative analysis of intraventricular blood flow dynamics by echocardiographic particle image velocimetry in patients with acute myocardial infarction at different stages of left ventricular dysfunction.

AIMS: Left ventricular (LV) diastolic filling is characterized by the formation of a vortex that supports an efficient transit into systolic ejection. Aim of this study was to assess the intraventricular (IV) blood flow dynamics among patients with ST elevated myocardial infarction (STEMI) at different degrees of LV dysfunction, in the attempt to find novel indicators of LV pump efficiency. METHODS AND RESULTS: Sixty-four subjects, 34 consecutive STEMI patients and 30 healthy controls, underwent before hospital discharge 2D speckle tracking echocardiography to assess global longitudinal strain (GLS), and echo-particle image velocimetry analysis to assess flow energetic parameters. Left ventricular volumes ejection fraction (LVEF) and global wall motion score index (GWMSI) were evaluated by 3D echocardiography. ST elevated myocardial infarction patients were subdivided into three groups according to LVEF. Energy dissipation, vorticity fluctuation, and kinetic energy fluctuation indexes, which characterize the degree of disturbance in the flow, exhibit a biphasic behaviour in STEMI patients when compared with controls, with the highest values in patients with still preserved LV function and progressive lower values with LV function worsening. Significant linear correlations were found between energy dissipation index and both LVEF and GLS (r = 0.57, P < 0.001 and r = -0.61, P = 0.001, respectively). Kinetic energy fluctuation index significantly correlates with both LVEF (r = 0.75, P < 0.001) and GLS (-0.58, P = 0.002). Finally, a significant correlation was observed between GWMSI and energy dissipation index (-0.56, P = 0.008). CONCLUSIONS: The present study describes, for the first time, the progression of IV flow energetic properties in patients with acute myocardial infarction at different stages of LV dysfunction when compared with healthy controls. Further data are needed to assess the role of these parameters in the development and maintenance of LV dysfunction.

Global and regional longitudinal strain assessed by two-dimensional speckle tracking echocardiography identifies early myocardial dysfunction and transmural extent of myocardial scar in patients with acute ST elevation myocardial infarction and relatively preserved LV function.

AIMS: Global and regional longitudinal strain (GLS-RLS) assessed by two-dimensional speckle tracking echocardiography (2D-STE) are considered reliable indexes of left-ventricular (LV) function and myocardial viability in chronic ischaemic patients when compared with delayed-enhanced cardiac magnetic resonance (DE-CMR). In the present study, we tested whether GLS and RLS could also identify early myocardial dysfunction and transmural extent of myocardial scar in patients with acute ST elevation myocardial infarction (STEMI) and relatively preserved LV function. METHODS AND RESULTS: Twenty STEMI patients with LVEF ≥40%, treated with PPCI within 6 h from symptoms onset, underwent DE-CMR and 2D-echocardiography for 2D-STE analysis 6 ± 2 days after STEMI. Wall motion score index (WMSI) and LV ejection fraction (LVEF) were calculated by both methods. Infarct size and transmural extent of necrosis were assessed by CMR. GLS and RLS were obtained by 2D-STE. Mean GLS of the study population was -14 ± 3.3, showing a significant correlation with both LVEF and WMSI, by CMR (r = -0.86, P = 0.001, and r = 0.80, P = 0.001, respectively) and time-to-PCI (r = 0.66, P = 0.038). A weaker correlation was found between GLS and LVEF and WMSI assessed by 2D-echo (r = -0.65, P = 0.001, and r = 0.53, P = 0.013, respectively). RLS was significantly lower in DE-segments when compared with normal myocardium (P < 0.0001). A cut-off value of RLS of -12.3% by receiver-operating characteristic (ROC) curves identified DE-segments (sensitivity 82%, specificity 78%), whereas a cut-off value of -11.5% identified transmural extent of DE (sensitivity 75%, specificity 78%). CONCLUSION: Our findings indicate that RLS and GLS evaluation provides an accurate assessment of global myocardial function and of the presence of segments with transmural extent of necrosis, with several potential clinical implications.

Enhancement of anxiety, facilitation of avoidance behavior, and occurrence of adult-onset obesity in mice lacking mitochondrial cyclophilin D.

In this report, we have assessed the behavioral responses of mice missing the Ppif gene (CyPD-KO), encoding mitochondrial cyclophilin D (CyPD). Mitochondrial CyPD is a key modulator of the mitochondrial permeability transition which is involved in the regulation of calcium- and oxidative damage-induced cell death. Behavioral screening of CyPD-KO mice (ranging between 4 and 15 months of age) was accomplished using a battery of behavioral paradigms which included testing of motor functions, exploratory activity, and anxiety/emotionality, as well as learning and memory skills. We found that, compared with wild-type mice, CyPD-KO mice were (i) more anxious and less explorative in open field and elevated plus maze and (ii) performed better in learning and memory of avoidance tasks, such as active and passive avoidance. However, the absence of CyPD did not alter the nociceptive threshold for thermal stimuli. Finally, deletion of CyPD caused also an abnormal accumulation of white adipose tissue resulting in adult-onset obesity, which was not dependent on increased food and/or water intake. Taken together, our results suggest a new fundamental role of mitochondrial CyPD in basal brain functions and body weight homeostasis.

p66SHC promotes T cell apoptosis by inducing mitochondrial dysfunction and impaired Ca2+ homeostasis.

p66Shc, a redox enzyme that enhances reactive oxygen species (ROS) production by mitochondria, promotes T cell apoptosis. We have addressed the mechanisms regulating p66Shc-dependent apoptosis in T cells exposed to supraphysiological increases in [Ca2+]c. p66Shc expression resulted in profound mitochondrial dysfunction in response to the Ca2+ ionophore A23187, as revealed by dissipation of mitochondrial transmembrane potential, cytochrome c release and decreased ATP levels. p66Shc expression also caused a dramatic alteration in the cells' Ca2+-handling ability, which resulted in Ca2+ overload after A23187 treatment. The impairment in Ca2+ homeostasis was ROS dependent and caused by defective Ca2+ extrusion due at least in part to decreased plasma membrane ATPase (PMCA) expression. Both effects of p66Shc required Ca2+-dependent serine-36 phosphorylation. The mitochondrial effects of p66Shc were potentiated by but not strictly dependent on the rise in [Ca2+]c. Thus, Ca2+-dependent p66Shc phosphorylation causes both mitochondrial dysfunction and impaired Ca2+ homeostasis, which synergize in promoting T cell apoptosis.

Apoptosis to necrosis switching downstream of apoptosome formation requires inhibition of both glycolysis and oxidative phosphorylation in a BCL-X(L)- and PKB/AKT-independent fashion.

Human T-lymphoma Jurkat cells treated with several intrinsic death stimuli readily undergo a stepwise apoptotic program. Treatment with 1,9-dideoxyforskolin (ddFSK), an inactive analogue of the adenylate cyclase activator forskolin, induces necrotic cell death and switches to necrosis the response to the apoptosis inducers in Jurkat and in other cell models. Yet, in the presence of ddFSK, mitochondrial changes are enhanced and apoptosome formation takes place. We show that ddFSK does not inhibit the catabolic steps of apoptosis, but rather elicits a profound ATP depletion that in turn tunes the mode of cell demise towards necrosis. Treatment with ddFSK impairs both glycolysis and oxidative phosphorylation in a Bcl-X(L)- and PKB/Akt-independent fashion, and inhibition of both processes is needed to affect apoptosis progression. Apoptosis is not blocked per se by ATP depletion, as engagement of the Fas receptor directly activates caspases, thus bypassing ddFSK inhibition.

A mitochondrial perspective on cell death.

The role of mitochondria as crucial participants in cell death programs is well established, yet the mechanisms responsible for the release of mitochondrial activators and the role of BCL2 family proteins in this process remain controversial. Here, we point out the limitations of current approaches used to monitor the physiological responses of mitochondria during cell death, the implications arising from modern views of mitochondrial structure, and briefly assess two proposed mechanisms for the release of mitochondrial proteins during apoptosis.

Arachidonic acid causes cell death through the mitochondrial permeability transition. Implications for tumor necrosis factor-alpha aopototic signaling.

We have investigated the effects of arachidonic and palmitic acids in isolated rat liver mitochondria and in rat hepatoma MH1C1 cells. We show that both compounds induce the mitochondrial permeability transition (PT). At variance from palmitic acid, however, arachidonic acid causes a PT at concentrations that do not cause PT-independent depolarization or respiratory inhibition, suggesting a specific effect on the PT pore. When added to intact MH1C1 cells, arachidonic acid but not palmitic acid caused a mitochondrial PT in situ that was accompanied by cytochrome c release and rapidly followed by cell death. All these effects of arachidonic acid could be prevented by cyclosporin A but not by the phospholipase A(2) inhibitor aristolochic acid. In contrast, tumor necrosis factor alpha caused phospholipid hydrolysis, induction of the PT, cytochrome c release, and cell death that could be inhibited by both cyclosporin A and aristolochic acid. These findings suggest that arachidonic acid produced by cytosolic phospholipase A(2) may be a mediator of tumor necrosis factor alpha cytotoxicity in situ through induction of the mitochondrial PT.

The mitochondrial permeability transition, release of cytochrome c and cell death. Correlation with the duration of pore openings in situ.

We investigated the relationship between opening of the permeability transition pore (PTP), mitochondrial depolarization, cytochrome c release, and occurrence of cell death in rat hepatoma MH1C1 cells. Treatment with arachidonic acid or induces PTP opening in situ with similar kinetics, as assessed by the calcein loading-Co(2+) quenching technique (Petronilli, V., Miotto, G., Canton, M., Colonna, R., Bernardi, P., and Di Lisa, F. (1999) Biophys. J. 76, 725-734). Yet depolarization, as assessed from the changes of mitochondrial tetramethylrhodamine methyl ester (TMRM) fluorescence, is rapid and extensive with arachidonic acid and slow and partial with. Cyclosporin A-inhibitable release of cytochrome c and cell death correlate with the changes of TMRM fluorescence but not with those of calcein fluorescence. Since pore opening must be accompanied by depolarization, we conclude that short PTP openings are detected only by trapped calcein and may have little impact on cell viability, while changes of TMRM distribution require longer PTP openings, which cause release of cytochrome c and may result in cell death. Modulation of the open time appears to be the key element in determining the outcome of stimuli that converge on the PTP.

Mitochondria and cell death. Mechanistic aspects and methodological issues.

Mitochondria are involved in cell death for reasons that go beyond ATP supply. A recent advance has been the discovery that mitochondria contain and release proteins that are involved in the apoptotic cascade, like cytochrome c and apoptosis inducing factor. The involvement of mitochondria in cell death, and its being cause or consequence, remain issues that are extremely complex to address in situ. The response of mitochondria may critically depend on the type of stimulus, on its intensity, and on the specific mitochondrial function that has been primarily perturbed. On the other hand, the outcome also depends on the integration of mitochondrial responses that cannot be dissected easily. Here, we try to identify the mechanistic aspects of mitochondrial involvement in cell death as can be derived from our current understanding of mitochondrial physiology, with special emphasis on the permeability transition and its consequences (like onset of swelling, cytochrome c release and respiratory inhibition); and to critically evaluate methods that are widely used to monitor mitochondrial function in situ.

Chloromethyltetramethylrosamine (Mitotracker Orange) induces the mitochondrial permeability transition and inhibits respiratory complex I. Implications for the mechanism of cytochrome c release.

We have investigated the interactions with isolated mitochondria and intact cells of chloromethyltetramethylrosamine (CMTMRos), a probe (Mitotracker Orange) that is increasingly used to monitor the mitochondrial membrane potential (Deltapsi(m)) in situ. CMTMRos binds to isolated mitochondria and undergoes a large fluorescence quenching. Most of the binding is energy-independent and can be substantially reduced by sulfhydryl reagents. A smaller fraction of the probe is able to redistribute across the inner membrane in response to a membrane potential, with further fluorescence quenching. Within minutes, however, this energy-dependent fluorescence quenching spontaneously reverts to the same level obtained by treating mitochondria with the uncoupler carbonylcyanide-p-trifluoromethoxyphenyl hydrazone. We show that this event depends on inhibition of the mitochondrial respiratory chain at complex I and on induction of the permeability transition pore by CMTMRos, with concomitant depolarization, swelling, and release of cytochrome c. After staining cells with CMTMRos, depolarization of mitochondria in situ with protonophores is accompanied by changes of CMTMRos fluorescence that range between small and undetectable, depending on the probe concentration. A lasting decrease of cellular CMTMRos fluorescence associated with mitochondria only results from treatment with thiol reagents, suggesting that CMTMRos binding to mitochondria in living cells largely occurs at SH groups via the probe chloromethyl moiety irrespective of the magnitude of Deltapsi(m). Induction of the permeability transition precludes the use of CMTMRos as a reliable probe of Deltapsi(m) in situ and demands a reassessment of the conclusion that cytochrome c release can occur without membrane depolarization and/or onset of the permeability transition.

Commitment to apoptosis by GD3 ganglioside depends on opening of the mitochondrial permeability transition pore.

We have studied the effects of GD3 ganglioside on mitochondrial function in isolated mitochondria and intact cells. In isolated mitochondria, GD3 ganglioside induces complex changes of respiration that depend on the substrate being oxidized. However, these effects are secondary to opening of the cyclosporin A-sensitive permeability transition pore and to the ensuing swelling and cytochrome c depletion rather than to an interaction with the respiratory chain complexes. By using a novel in situ assay based on the fluorescence changes of mitochondrially entrapped calcein (Petronilli, V., Miotto, G., Canton, M., Colonna, R., Bernardi, P., and Di Lisa, F. (1999) Biophys. J. 76, 725-734), we unequivocally show that GD3 ganglioside also induces the mitochondrial permeability transition in intact cells and that this event precedes apoptosis. The mitochondrial effects of GD3 ganglioside are selective, in that they cannot be mimicked by either GD1a or GM3 gangliosides, and they are fully sensitive to cyclosporin A, which inhibits both the mitochondrial permeability transition in situ and the onset of apoptosis induced by GD3 ganglioside. These results provide compelling evidence that opening of the permeability transition pore is causally related to apoptosis.

Transient and long-lasting openings of the mitochondrial permeability transition pore can be monitored directly in intact cells by changes in mitochondrial calcein fluorescence.

The occurrence and the mode of opening of the mitochondrial permeability transition pore (MTP) were investigated directly in intact cells by monitoring the fluorescence of mitochondrial entrapped calcein. When MH1C1 cells and hepatocytes were loaded with calcein AM, calcein was also present within mitochondria, because (i) its mitochondrial signal was quenched by the addition of tetramethylrhodamine methyl ester and (ii) calcein-loaded mitochondria could be visualized after digitonin permeabilization. Under the latter condition, the addition of Ca2+ induced a prompt and massive release of the accumulated calcein, which was prevented by CsA, indicating that calcein release could, in principle, probe MTP opening in intact cells as well. To study this process, we developed a procedure by which the cytosolic calcein signal was quenched by Co2+. In hepatocytes and MH1C1 cells coloaded with Co2+ and calcein AM, treatment with MTP inducers caused a rapid, though limited, decrease in mitochondrial calcein fluorescence, which was significantly reduced by CsA. We also observed a constant and spontaneous decrease in mitochondrial calcein fluorescence, which was completely prevented by CsA. Thus MTP likely fluctuates rapidly between open and closed states in intact cells.

The role of mitochondria in the salvage and the injury of the ischemic myocardium.

The relationships between mitochondrial derangements and cell necrosis are exemplified by the changes in the function and metabolism of mitochondria that occur in the ischemic heart. From a mitochondrial point of view, the evolution of ischemic damage can be divided into three phases. The first is associated with the onset of ischemia, and changes mitochondria from ATP producers into powerful ATP utilizers. During this phase, the inverse operation of F0F1 ATPase maintains the mitochondrial membrane potential by using the ATP made available by glycolysis. The second phase can be identified from the functional and structural alterations of mitochondria caused by prolongation of ischemia, such as decreased utilization of NAD-linked substrates, release of cytochrome c and involvement of mitochondrial channels. These events indicate that the relationship between ischemic damage and mitochondria is not limited to the failure in ATP production. Finally, the third phase links mitochondria to the destiny of the myocytes upon post-ischemic reperfusion. Indeed, depending on the duration and the severity of ischemia, not only is mitochondrial function necessary for cell recovery, but it can also exacerbate cell injury.

Imaging the mitochondrial permeability transition pore in intact cells.

The involvement of mitochondrial permeability transition pore (MTP) in cellular processes is generally investigated by indirect means, such as changes in mitochondrial membrane potential or pharmacological inhibition. However, such effects could not be related univocally to MTP. In addition, source of errors could be represented by the increased retention of membrane potential probes induced by cyclosporin A (CsA) and the interactions between fluorescent probes. We developed a direct technique for monitoring MTP. Cells were co-loaded with calcein-AM and CoCl2, resulting in the quenching of the cytosolic signal without affecting the mitochondrial fluorescence. MTP inducers caused a rapid decrease in mitochondrial calcein fluorescence which, however, was not completely prevented by CsA. Besides the large and rapid efflux of calcein induced by MTP agonists, we also observed a constant and spontaneous decrease of mitochondrial calcein which was completely prevented by CsA. Thus, MTP likely fluctuates between open and closed states in intact cells.

The mitochondrial permeability transition.

This review summarizes recent work on the regulation of the permeability transition pore, a cyclosporin A-sensitive mitochondrial channel that may play a role in intracellular calcium homeostasis and in a variety of forms of cell death. The basic bioenergetics aspects of pore modulation are discussed, with some emphasis on the links between oxidative stress and pore dysregulation as a potential cause of mitochondrial dysfunction that may be relevant to cell injury.